Expert Python Programming - Second Edition

The naming guide

A common set of naming rules can be applied on variables, methods, functions, and properties. The names of classes and modules also play an important role in namespace construction, and in turn in code readability. This mini-guide provides common patterns and antipatterns for picking their names.

Using the has or is prefix for Boolean elements

When an element holds a Boolean value, the is and has prefixes provide a natural way to make it more readable in its namespace:

class DB:
    is_connected = False
    has_cache = False

Using plurals for variables that are collections

When an element is holding a collection, it is a good idea to use a plural form. Some mappings can also benefit from this when they are exposed like sequences:

class DB: ...